Inclinometer



Jan. 2, 1945. H. E. MALONE 2,356,346

INCLINOMETER Filed Aug. 1, 1942 2 Sheets-Sheet 1 NOSE BY HUMER E-MALUNE Wfi ATTORNEY.

INVENTOR. v

Jan. 2, 1945. H. E. MALONE INCLINOMETER Filed Aug. 1, 1942 2 Sheets-Sheet 2 I69 107 wt. /05

, INVENTOR. BY HUMER E--MALEINE fiwATToRNEY.

Patented m i UNITED;

2.366.346 v mcnmomz'ran E. Malone, Milwaukee, Wis assignor'to Perfex Corp ration, Miiwaukee, Wis, a corporation of Wisconsin Application August r, 1942, Serial No. 453,161 g 4' Claims. (Cl. 33-220)- This invention relates in metal to'indicating and controlling instruments and more particularly to instruments for indicating inclination and/or acceleration of aircraft or other cles and devices. In handling aircraft, it

vehi- This is especially desirable in the case of modern' bombing planes which carry their bombs in the fuselage. Such bombers must be fairly' level when the bombs are released in order that the bombs may fall from their racks through the bomb bay. doors. If the plane is inclined too far one way or the other when the bombs are released, there is danger that the bombs may strike the floor of the bombbay.

The primary object of this invention consists in the provision ofja simple and reliable instrument for indicating the inclination of the obiect upon which it is mounted. I

In such bombing planes, it is also important that the bombs arenot released if the plane is accelerating or decelerating beyond certain limits. Such acceleration ordeceleration has the same effect as inclination. Thlls if the plane is A further object of the invention is the' pro-' vision of an instrument ofthe type mentioned a is desirable to have I a reliable indication of the ship's inclination.

of Fig. 1; and

description and appended claims.

For a fulldisclosure of theinvention, reference is made tothe following detailed descrip- Other objects will appear from the following tion and t0 the. accompanying drawings, in which Fig. .1 is a cut-awayitop view: of the instrument, partly in section;

Fi 2 is a side view of. the instrument with the casing cut-away to show the interior construction; 1 I

Fig. 3 isa front view;

Fig. 4 is a fragmentary side view similar to Fig. 2, but showing the pointer adjustment mechanism;

Fig. 5 is a rearview taken on line 6-5 of Fig.2;

Fig. 6 is a sectional view taken on line 6-6 Fig. '1 is'a' view similar to Fig. 4 but showing amodiflcation. 1

' Referring to the drawings, reference character I indicates generally abase member having a hollow cylindrical front portion 2, this front portion being formed. with an integral mounting flange 3 for mounting the instrument upon a suitable instrument panel. Extending rearward- 'ly from-the front portion 2 are upper and lower shown in Fi 5 and being midway between the which is adapted for mounting upon an ins'trument panel, the indication of the inclination and/or acceleration being performed by a dial and pointer.

Another object consists in the provision of a condition responsive instrument with a simple vibration dampening arrangement which has minimum effect upon the. sensitivity of the instrument.

A further object consists in the provision of an instrument of the type described which actuates a controlling device such as a switch and which is readily adjustable for varying the point at which the switch is operated. Another, object consists in the provision of a simple arrangement for adjusting such instrument and for-indicating the adjustment thereof.

brackets l and 5 respectively. As shown in Fig. 5, the bracket I is arcuate in shape and is formed with downwardly depending flanges 6 and I at each side. The bracket 6 is similar to the brack- -et 4 but is provided with upwardly extending flanges inv alignment with the flanges 6 and I. The outer ends of the brackets 4 and 5 are joined by a web 8, this'web extending vertically as flanges 6 and 1.

The interior of the front portion 2 is formed with a shoulder 9 for receiving a generally circular cross plate Hi, this plate being held'ln place cross plate In. The dial is covered by a glass 20 held in place by a snap ring 2| Preferably suitable annular gaskets 22 are interposed between the back of' the glass and the retaining shoulder formed on the front portion 2 of base member I.

Reference character 25 indicates a wheel shaped member which forms a part of an inclination or acceleration responsive mechanism.

This member is provided at its center with an axle 26, the ends of which are preferably of com-- cal shape. One end of axle 23 is received in an insert 21 located in the vertically extendingweb 8. The other end of the axle is received in a counter-sunk adjusting screw 28. This adjust-.

ving screw is carried on a strip 28 (Fig. 5) which of the wheel member 25 facing the front of the" instrument carries a toothed ribbon member 32. This ribbon member issecured to the wheel 25 ture concentric with that ofthe periphery of the wheel. The teeth of the member 32 cooperate with a spur gear '33 which is-carried on a shaft 34. This shaft extends through the plates i and i4 and carries a pointer 35 which cooperates with the dial l4 to indicate the inclination of the instrument. The parts are arranged so that when the instrument is'level, the pointer asfact.

assets-1c combined with-inclination response is of considerable value as a guide in bombing operations. Thus if the plane's inclination is such that the bombs would not fall clear of the plane, the bombardier is given notice of this fact. Similarly. if the plane is accelerating or decelerating to such an extent that it would be unsafe to drop the bombs, the instrument'will indicate this In'addition, the instrument willintegrate the combined efleotof inclination and acceleration of the plane so as to indicate any unsafe condition caused by such combined effects.

It is desirable to provide pointers 38 and. 39

- cooperating with the dial l4 for indicating the at a number of points so that it assumes a curvasafe limits at which the bombs can be dropped. Preferably 'these pointers should be readily adjustable so that they may be set in accordance with the characteristics of the bomb load being carried. In the embodiment shown in Fig. 3. the pointer 38 is adjusted by aflmob 40 and the pointer 39 is adjusted by. knob 4|. The mechanism for providing such adjustment will now be described.

The pointer .38 extends through a slot 42 (Figs. 1, 4 and 6) between the base member and dial and is carried by a gear segment 43. The pointer 39 extends through a similar. slot 44 and is carried by a gear segment 45. These gear segments are carried by a stationary hub member 45 through which the shaft 34 extends.

' to the dial plate 14 and the rear of this memsumes the zero position on the dial, as shown in Fig. 3. If the instrument is tilted counter-clockwise, as seen in Fig. 2, the wheel 5 will remain stationary due to the'weight 30. The gear 33 at this time, however; will moveupwardly relative .to the toothed member 32, thus causingthe gear 33 to rotate clockwise as seen from the front of the instrument. Thus the pointer 35 will be caused to indicate the degree of inclination of the instrument on the lower portion of the dial I4. If the instrument is rotated clockwise from the level position, the needle 35 will indicate the degree of inclination on the upper portion of the. dial l4.

ber is formed with a flange 41 which is engaged by the gear segment 45. Suitable spacing and friction washers 49 are provided on each side of the gear segment 44. The washers and gear segments are held in position by means of a spiral spring member 50 interposed between the front spacing washer and the dial plate M. This arrangement holds the gear segments 44 and 45 in tight but adjustable relationship.

The gear segment 44 is rotated by a pinion gear 52 which is carried by a shaft 53. This shaft extends through plate l0, dial i4 and glass It will be noted that the wheel member as is relatively massive in construction relative to ,the weight 30. It will also be notedthat the major portion of themass of the wheel 25 is substantially spaced. from the axle 26. This imparts a substantial rotationalmoment of inertia to the inclination responsive structure. This moment of inertia is quite large as com-. pared to the force produced by the unbalanced weight 30. This arrangement serves .to

effectively dampen oscillation of the responsive member. This dampening requires no fric tion whateverin the parts. Consequently the instrument may be formed as friction free as,

possible so as to provide extremeaccuracy in the measurement and indication of inclination.

It should be noted that the inclination responsive device above described is also responsive to acceleration. Thus if the plane in which the instrument is mounted should accelerate, the weight 30 will tend to be left behind. This will cause the wheel 25 to rotate counter-clockwise,

as seen in Fig. 2, to a position in which the lat-- eral component of force balances the force of acceleration. If the ,plane should decelerate, the opposite action will occur',that is, the wheel 25 will rotate clockwise as seen inFig. 2, and thus rotate the needle 35 clockwise as seen in Fig. 3. This acceleration responsive feature 20, and at its outer end carries the knob 40 which is held in place by set screw 54. The other end of the shaft 53' is carried by an inturned portion 55 of a U-shaped bracket member 56. This bracketmember is fastened by screws 51 (Fig. 5-) to a strip 58 which'is secured to the leg I of the upper bracket 4 and to the corresponding leg of the lower bracket 5. It will be apparent that when the knob 40 is rotated the gear segment. will be rotated, thereby moving the pointer 38 along the periphery of the dial. The gear segment 45 is rotated by a pinion gear 60 carried bya shaft 6|,this shaft at its outer end carrying the adjusting knob 4|, and at its inner end engaging an in-turned portion 62 of the U-shaped bracket member 63. This bracket member is secured to the strip 29 by means of screws 64.

In some cases it is desirable to actuate control devices, such as switches, when the inclination .The front end of this hub member is attached 2,866,846 wheel 85 is provided with a U-shaped weight I8 similar to the weight 88 on wheel, 25. The wheel 55 is also provided with a bracket member .II

which is adapted to actuate switches generally indicated as I2 and 18.

Referring tothe switch I2, this switch is formed of a relatively stiif blade ll-and 9, flexible blade I5 having suitabl contacts at their outer ends. These switcli blades extend through an arcuate slot I8 formed in the wheel 85 and are attached to a member I1 of insulating mate 1 rial. The member 11 is carried by the free .end

is carried by the screw-threaded inner end of the shaft 58. The other end of the strip 8I is attached to a spring 8l, the other end of which is secured to the cross plate I8. The mid-portion of the strip 8I is attached by screw 8Ia to the pulley 88 for preventing any slipping 0f this strip on the'pulley. Itwill be apparent that of a lever arm I8 which is pivoted to a shaft Y wardly extending U-shaped bracket-9| which is secured'to the rear faces of the bracket member's.-v l and 5. The: instrument mechanism is preferably protected by a casing 92 which is-held in place by screws '88-,carried by bracket9I.

Referring to Fig. 7. this figure shows. a 'modified arrangement for adjusting the'markerson the dial. In this figure, the knob l8a is adapted toadjust one marker when it is pushed in, and

to adjust the other marker when it is pulled out.

In this embodiment of the invention, the gear segment lla adjusts the marker 88a, and the gear segment l5a adjusts the othermarker, not

- shown. These gear segments are mounted in a rotation of the knob l8 will rotate the shaft 58, thereby causing longitudinal movement of the traveling nut 88, this in turn causing r'otation of the lever I8 about its pivot.- Thus rotation of the knob l8 serves to vary the angular position of the lever arm I8 and thus bodily shifts the switch 12 concentrically with thewheel 85. 'It will be apparent that the flexible blade 15 is biased away from the rigid blade ll of the switch I2. However, when the instru- .ment is tilted clockwise, as seen in Fig. 2, the

bracket member 'II will'remain stationary, while the switch I2 will be raised bodily toward the bracketmember. When the instrument is tilted to the predetermined point, the flexible switch member I5 will engage th bracket member II and thus remain stationary until the rigid switch blade I2 contacts it for closing the switch. By rotating the,lever I8 about its pivot the degree of clockwise inclination at which switch I2 closes may' be adjusted. 'It will be apparent that by properly arranging the parts, the pointer 88 which is actuated by the knob-l8, may be caused to indicate the inclination at which switch I2 closes. It should here be noted that the adjusting mechanism for the pointer 88 and the adjusting mechanism for the switch I2 ar both straight line mechanisms, that is, the movements of the pointer and switch are in straight line relationship with movement of the knob l8. Consequently th pointer 88 will indicate accurately the adjustment of the switch throughout" manner similar to the corresponding segments in Fig. .1. However, in this case'the friction washerarrangement -is somewhat modified. In order-to prevent movement of one gear segment from causing movement of the other segment, a stationary plate 95 is interposed between the two gear'segments. This lat is held station-- ary by means of a pin 88 having one end supported in the dial' plate I la, and its other end secured to a. cross plate Illa. The gear segments lla; and l 5a are provided with arcuate slotsv through which'th pin 88 extends, this arrangement permitting rotation of the gear se ments within predetermined limits. Suitable friction washersy9l and 88 are located on each side of the stationary plate 95 and engage the gear segments l5a and lla respectively. A spacing washer 99 is interposed between the gear segment 88 and the dial plate I8, and a spring '1 member 58a is interposed between the gear segment l5a and the cross plate l8a This arrange-- ment holds the various parts in th relation shown its entire range of adjustment.

The switch I3 is similar in construction to-the switch 12 and extends through a slot in the wheel 25. This switch is carried by a lever 85 which is rotated about its pivot in the same manner as 'lever 18 by a traveling nut 88 carried on the shaft 8|. Thus rotation of the adjusting knob lI serves to adjust the switch I8 and also to adjust the pointer 88 so as. to indicate the adjustment of this switch. The traveling nuts 83 and 88 are preferably provided with pins 88 and 89 which engage suitableslots formed in the strips 58 and 29. This arrangement serves to ;preventrotation of the nuts.

The switches-I2 and I3 are connected by pig tail connections (not shown) to an electrical connector member 98 of usual construction. This connector member is supported upon a rear-v and impartsfriction to the gear segments lla and l5a, andthus holds the segments in stationary but adjustable relationship. Preferably an arrangement is provided for adjusting the amount of friction which holds the gear segments in place. In the present embodiment of the invention this friction'adiustment consists of screws I88 which extend through plates -I8a and Ila, the gear segments being provided with The arcuate slots for receiving such screws. screws I88 alsoserve to secure the dial plate Ila to the cross plat I8a.,' I

v The gear segments lla and l5a mesh with spaced idler gears IN and I82 which are carried by a shaft I88 attached to the cross plate I8a. These idler gears are adapted to cooperate with a gear I8l which is formed on the shaft I85 which carries the adjusting knob Ma. The left hand end of the shaft I85 is hollow, as indicated at I88, and fits over a' suitable hollow guide bushing I8'I which is carried bythe' cross plate I8. .A spring I88 surrounds the shaft I85 and serves to press this shaft inwardly. A pin I88 extends through the hollow guide bushing I81 inwardly by a leaf spring I I 8 which is secured a to the cross plate I8a. With the parts in their normal positions, it will be observed that the spring I88 serves to press the shaft I85 inwardly and that the spring II8 acts through pin I89 to press this shaft outwardly. The spring H8 is formed strong enough to overcome spring I88 and thus the shaft I85 is pressed outwardl until spring II8 engages bushing I81. 1 Thus the gear IN is normallyheld in the position shown in which it is disengaged from both idler gears. When it is desired to adjust the pointer 88a, the knob l8a is pulled outwardly against the action utility is not limited to such,use.

it is desired to adjust the other pointer, the knob "a is pushed inwardly against the actionl of spring H0, this causing the'gear IM to engage the idler gear llll. Thus when the knob Ilia is now rotated, the gear segment 45a will heretated and thus the other marker will be adjusted. When knob 40a is released, the spring III! will return the parts to the neutral position as shown. l I

From the foregoingdescription it will be seen that the present invention provides a very accurate inclination and/or acceleration responsive aseasse of the responsive member with respect to the base structure, an adjustable marker on the dial, an

adjusting screw extending forwardly of the dial for adjusting said marker, a control member arranged for actuation by said responsive member,

' adjustable mounting means for said control memtate the same, a spring attached to one end of tlieriiexible member, a travelling nut carried by her, said mounting means being rotatable about a pivot in substantial alignment with the pivot of said responsive member, a pulley for rotating said adjustable mounting means, an elongatedv flexible member engaging the pulley so as to rosaid adjusting screw, the other end of the elongated member being attached to said travelling nut.

3. A control instrument comprising, a control device, rotatable adjusting means for adjusting device in which the parts may be made entirely free of friction, and in which oscillation is nevertheless effectively dampened. It will also be seen that this arrangement is adapted to'either actuate an indicating device, such as a pointer,

or to operate suitable control devices, such as switches. It will -a-lsd'be seen that the present invention provides a simple and practical arrangement for adjusting the point at which the control devices are actuated and for indicating the adjustment of such control devices. While the invention is particularly useful as a safety indicating device for bombing operations, its Inasmuch as many modifications and applications may be made without departing from the scope of the invention, it is desired to be limited only by the appended claims.

What is claimed is:

1. An instrument of the character described comprising, a base structure, a dial carried by said base structure, a pivoted responsive member located behind the dial and arranged to rock about its pivot in a direction perpendicular to the dial, means including a pointer cooperating with the dial for indicating the angular position of the responsive member with respect to the base structure, an adjustable marker on the dial, an adjusting screw extending forwardly of the dial for adjusting said marker, a control member arranged for actuation by said responsive member, adjustable mounting means for said control member, said mounting means being rotatable about a pivot in substantial alignment with the pivot of said responsive member, and

means actuated by said adjusting screw for ro-v said control device, a pulley for rotating said rotatable adjusting means, an. elongated flexible member engaging said pulley so as to rotate the same, a spring attached to one end of the flexible member, an adjusting screw, a travelling nut carried by said adjusting screw, the other end of said flexible member being connected to said travelling nut. I

I 4. A device of the characterdescribed comprising, a base structure, a dial carried by said base structure, a Pointer also carried by said base structure and cooperating with said dial, a shaft for rotating the pointer, a gear engaging the shaft for rotating the same, a wheel shaped structure disposed perpendicular of the dial and pivoted to the base structure, said wheel shaped structure being formed with a substantial portion of its mass asubstantially spaced from the pivot so as to provide a relatively large rotational moment of inertia for dampening oscillation, said wheel shaped structure also being constructed so that its pivot is slightly oif center with respect to its center of gravity whereby it tends to assume a fixed position due to the effect of gravity, said with the dial for indicating the angular position wheel shaped structure also being formed as a gear at a part of its periphery for engaging said first mentioned gear whereby the dial and pointer indicate the relative positions of the wheel shaped structure and base structure, a pair of markers cooperating with said. dial for indicating predetermined limits of inclination, a first gear located behind the dial for carrying one of said pointers, a second gear located behind the dial for carrying the other of said pointers, a single adjusting shaft extending forwardly of said dial for adjusting both of said pointers, said shaft being movable longitudinally and carrying gear means adapted to selectively engage one or the other of said gears, and spring biasing means for biasing said shaft to an intermediate longitudinal position in which the g ar means is disengaged from both of said gears.

, HOMER E. MALONE. 

